System for mixing opposite polarity ions on magnetic field axis



Feb. 13, 1968 w 1 c coc 3,369,148

SYSTEM FOR MIXING OPPOSITE POLARITY IONS ON MAGNETIC FIELD AXIS Filed July 5, 1961 2 Sheets-Sheet '1 A. C. F0662." 600K635 INVENTOR. M4

Feb. 13, 1968 w. J. HITCHCOCK SYSTEM FOR MIXING OPPOSITE POLARITY IONS ON MAGNETIC FIELD AXIS Filed July 5, 1961 2 Sheets-Sheet 2 h EU fiIW/HZV/hz/ /A fl///////// ///n/n/v$ 7:

INVENTOR.

United States Patent 3,369,148 SYSTEM FOR MIXING OPPOSITE POLARITY IONS 0N MAGNETIC FIELD AXIS William .I. Hitchcock, 164 Main St., Kingston, Mass. 02360 Filed July 5, 1961, Ser. No. 122,040 11 Claims. (Cl. 315-111) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

This invention relates generally to the generation of ions and more particularly to a method and apparatus for increasing the density of hydrogen ions.

Previously, ions have been generated by emission from metallic points under the influence of very high D.C. electric fields. An example of an apparatus operating under this principle may be found in the patent to Raymond G. Herb, Patent No. 2,809,314, Oct. 8, 1957. Another example is some of the work done on field emission microscopes. Then density of ions, as distinguished from electrons, produced by the prior art methods has been found to be too small, especially for application to thermonuclear machines and their main usefulness is source of high voltage.

This invention provides for a change in the high elec tric field of prior art devices to increase the density of ions that are produced without the electrical breakdown which usually accompanies the use of DC. fields. In addition an arrangement of ion sources is provided for an adding of densities from each source to produce a higher density output than may be attained by a single source or other arrangements of multiple sources.

Accordingly, it is an object of this invention to provide an ion source capable of producing a beam of ions of greater density than that heretofore achieved.

It is another object of this invention to produce an ion source suitable for use in particle accelerators, hydrogen fusion apparatus, ion propulsion or any apparatus in which high density ions may be desired.

It is still another object of this invention to provide an arrangement of ion sources to provide a high density ion beam within a separately excited solenoid to cause a high temperature there.

These and other advantages, features and objects of the 111V6I1tl0n will become more apparent from the followmg description taken in connection with the illustrative embodiments in the accompanying drawings, where- FIGURE 1 is a sectional view of the invention;

FIGURE 2 is a schematic diagram illustrating the high voltage supply for the apparatus of FIGURE 1;

FIGURE 3 is a schematic arrangement of ion sources to produce an increased density;

FIGURE 4 is a top view of the arrangement of FIG- URE 3 taken along line IV-IV.

The ion source of this invention, shown at 40 in FIG. 1, provides for field emission of ions externally from a metallic point wherein the point is interiorly fed a gas to be ionized. A high voltage field is made to act at the sharply rounded point to separate the ionized gas from the point.

Field emission ions may be either positive or negative and the gas utilized may be of any of the isotopes of hydrogen, for example, deuterium and tritium. The gas is supplied under pressure to the interior of a hollow needle which is usually heated initially by conventional means such as a heating coil 12 located near the point 14 of the needle. The gas under greater pressure within the needle permeates through the walls of the needle and forms a layer of ions which can flow toward the point of the needle. Gas which is pulled off from the point 14 is replenished by the additional permeation and flow of gas through the walls and along the outer surface of the needle 10. The needls may be of any material which is permeable to the gas such as palladium, nickel,

iron or titanium. It might also be an alloy such as silverpalladium.

The point is enclosed in an evacuated, grounded container 16 which contains accelerating electrodes 18, 20 and 22 which are supported on discs 24. The use of all of the acceleration grids is optional as they merely aid in collimating the resultant ion beam. The gas at the heated point 14 of the needle is removed as ions by a high electrical field at the point, such that a large potential gradient exists between the electrode system 18, 20 and 22 and the point 14. The spacing of these electrodes is so adjusted that there is no electrical breakdown with the frequencies used.

At this point, the structure is similar to that of the aforementioned patent to Herb; however, the generation of the field, schematically depicted in FIGURE 2 is different and aids in the increasing of the density of the ion beam while allowing for a higher intensity of electric field without electrical breakdown provided the field is formed at a very fast rate. T. Franzini (Nuero Cimento, Ser. 8, 15 :8899, 1938) utilized a DC. electric field on hydrogen passed through warm palladium in order to produce either protons or negative hydrogen ions. Such particles were freed from the paladium surface prior to recombination; however, only a small fractional number of ions were produced from a given flux of hydrogen. Increasing the DC. voltage gradient would create a problem of electrical breakdown in the hydrogen.

By superimposing a high voltage of alternating current on a relatively small direct current field and utilizing microwave frequencies or thereabouts, the breakdown of molecular hydrogen is avoided and the gas at point 14 is to a greater extent drawn oil? as ions. The sign of the DC. voltage determines the kind or of ions.

The electrode system 18, 20 and 22 and the electric field may be powered by the circuit schematically represented in FIGURE 2. In this figure a source of high frequency AC. or pulsed or rectified AC. is impressed on a DC. voltage source and applied to the point. With unfiltered, rectified A.C. no DC. bias is needed. Electrode 20 is at a potential between the needle and ground since it is connected to the movable element of 24. Thus a collimation of a dense, ionized beam is achieved. A magnetic field may also be used for collimation.

A number of units, as depicted in FIGURE 1, are arranged as shown in FIGURESS and 4 in order to achieve a greater density of ions. In this embodiment, as in FIG- URE 1, the particular gun electrode system shown in FIGS. 1 and 2 may be omitted; however, it is preferred to utilize an electrostatic focussing in order to accelerate the ions as well as join them into a beam.

A coil 30 is provided and attached to a source of electrical energy to create a magnetic field. In FIGURE 3 the ions spiral around the magnetic lines of force of the magnetic field, some lines of which are shown in dashed lines representing orbits.

By placing the ion sources 40 of FIGURE 1 in a back to back relationship in a vacuum as shown in FIGURES 3 and 4 and causing the coil 30 to generate a magnetic field to cause orbiting of the ions, and by adding a separate positive ion source 32 and a negative ion source 34 on opposed sides along the axis, the magnetic field of these ion beams would add. Thus, cyclotron radiation would produce light even in the ultra violet region. In addition, the density of the ions within the coil is increased to the extent that it would be possible to produce useful hydrogen fusion with the proper acceleration and density of the ions.

Thus, the addition of many sources in accordance with the arrangement and FIGURES 3 and 4 could be utilized either as a source of black or ultra violet light or as a hydrogen fusion device.

Although the invention has been described with reference to particular embodiments, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.

What is claimed is:

1. A high density ion source comprising a hollow member having at least a part of which is permeable to a gas and having at least one point on its external surface means to introduce said gas into said hollow member, and means comprising a source of high voltage alternating current connected with a low voltage direct current source for producing an electric field at said point to cause removal of said gas as ions in the vicinity of said point, said alternating current voltage being superimposed on said direct current voltage.

2. An ion source as defined in claim 1 wherein said alternating current source is at microwave frequencies and is pulsed.

3. A high density ion source comprising a hollow member having at least a part of which is permeable to an isotope of hydrogen and having at least one point on its external surface, heating means and a source of energy therefor for heating said point, means to introduce said isotope of hydrogen into said hollow member, and means comprising a source of high voltage alternating current and a low voltage direct current source for producing an electric field at said point to cause removal of ions of said isotope of hydrogen from the vicinity of said point, said alternating current voltage being superimposed on said direct current voltage.

4. An apparatus for adding ions from a number of ion sources to a volume to provide high density ions comprising a source of electrical energy, a coil connected with said source to cause a magnetic field, a series of ion sources arranged to emit ions parallel to the longitudinal axis of said coil and within the field of said coil, said ion sources being located proximate to the central transverse axis of said coil, and a second series of ion sources arranged to emit ions parallel to the longitudinal axis of said coil and within the field of said coil, said second series being located proximate to the central transverse axis of said coil and arranged to emit ions in a direction opposite to that of said first series.

5. An apparatus as defined in claim 4 including a source of positive ions located at one end of said coil along the longitudinal axis of said coil, and a source of negative ions located along said longitudinal axis at the other end of said coil.

6. An apparatus for adding ions from a number of ion sources to produce a volume of high density ions compris ing a source of electrical energy, a coil connected with said source to cause a magnetic field, a series of ion sources arranged in a 'back-to-back relationship within the field of said coil to emit ions in opposite directions along an axis parallel to the longitudinal axis of said coil.

7. An apparatus as defined in claim 6 including a source of positive ions located at one end of said coil along the longitudinal axis of said coil, and a source of negative ions located along said longitudinal axis at the other end of said coil.

8. An apparatus as defined in claim 6 wherein each ion source of said series of ion sources comprises a hollow member having a point, means comprising a source of high voltage alternating current and a small direct current source for producing an electric field at said point to cause removal of said gas as ions in the vicinity of said point, said alternating current voltage being superimposed on said direct current voltage.

9. A high density ion source comprising a hollow member having at least a part of which is permeable to a gas and having at least one point on its external surface, means to introduce said gas into said hollow member, and means for producing an electric field at said point to cause removal of said gas as ions in the vicinity of said point, said last mentioned means producing an output which corresponds to an alternating current voltage being superimposed on said direct current voltage and comprises a high voltage half wave rectified alternating current source connected with a low voltage direct current source.

10. An apparatus for adding ions from a number of ion sources to a volume to provide high density ions comprising a source of electrical energy, a coil connected with said source to cause a magnetic field, and a series of ion sources arranged parallel to the longitudinal axis of said coil, external to said coil and within the field of said coil, some of said ion sources emitting ions in one of the two directions parallel with said longitudinal axis, and the remainder of said ion sources emitting ions in the other of the two directions parallel with said longitudinal axis.

11. An apparatus for adding ions from a number of ion sources to a volume to provide high density ions comprising a source of electrical energy, a coil connected with said source to cause a magnetic field, and a series of ion sources arranged parallel to the longitudinal axis of said coil, external to said coil in a plane proximate to the central transverse axis of said coil and Within the field of said coil.

References Cited UNITED STATES PATENTS 2,754,442 7/1956 Boutry et al 3 l3230 X 2,809,314 10/ 1957 Herb 313230 X 3,014,154 12/ 1961 Ehlers et al 313-2315 ROBERT SEGAL, Primary Examiner.

GEORGE WESTBY, RALPH NILSON, Examiners.

D. E. SRAGOW, C. R. CAMPBELL,

Assistant Examiners. 

6. AN APPARATUS FOR ADDING IONS FROM A NUMBER OF ION SOURCES TO PRODUCE A VOLUME OF HIGH DENSITY IONS COMPRISING A SOURCE OF ELECTRICAL ENERGY, A COIL CONNECTED WITH SAID SOURCE TO CAUSE A MAGNETIC FIELD, A SERIES OF ION SOURCES ARRANGED IN A BACK-TO-BACK RELATIONSHIP WITHIN THE FIELD OF SAID COIL TO EMIT IONS IN OPPOSITE DIRECTIONS ALONG AN AXIS PARALLEL TO THE LONGITUDINAL AXIS OF SAID COIL. 